Introduction:Considering that only some and not all smokers develop chronic
obstructive pulmonary disease (COPD), there may be other factors responsible
for the development of COPD among smokers. Previous researchers have reported
that ethnicity could be one of factors associated with the development of COPD.
This study aimed to examine the factors associated with the development of
airflow limitation, suggestive of having COPD, among Korean smokers using data
from the Korea National Health and Nutrition Examination Survey conducted
over the past 3 years.

Methods:A total of 2569 current and former smokers ≥40 years of age were
included. Most studies exploring risk factors for COPD have compared smokers
and non-smokers with smoking as only one of the independent variables. In this
study, we took a different approach, studying only smokers and comparing those
with or without airflow limitation.

Results:The prevalence of airflow limitation among the study participants was
19.2% and 22.1% in current and former smokers, respectively. There was no
significant correlation between the severity of airflow limitation and total lifetime
smoking amount. Among the many variables examined, only age, male gender
and total lifetime smoking amount (pack-years) were significant factors associated
with the development of cigarette smoke-induced airflow limitation.

Conclusions:Older Korean men who are heavy smokers may be at a higher risk of
developing COPD. Our findings support the importance of smoking cessation as
the best way to prevent the development of COPD.

ACKNOWLEDGEMENTS

We are grateful to the Korea Centres for Disease Control and Prevention
for allowing us to use the Korea National Health and Nutrition
Examination Survey (KNHANES) data.

CONFLICTS OF INTEREST

Authors have completed and submitted the ICMJE Form for Disclosure
of Potential Conflicts of Interest and none was reported.

Korea Centers for Disease Control and Prevention. The work-shop report and guide to the utilization of the data from the Korea National Health and Nutrition Examination Survey. https://knhanes.cdc.go.kr/knha.... Accessed May 14, 2017.